Oh my crap, NO! That is THE FUNNIEST THING I've heard in ages.
YES, YES, YES, I think an EA can DEFINITELY be one-sided. After all, an EA is about giving thoughts, feelings, time, energy, emotions to someone OUTSIDE of your significant relationship. The fact that the feelings are/are not returned is immaterial to me.
I think an EA is kind of an 'addiction' of the emotions. People can be addicted to 'things': sex, gambling, drinking, drugs, porn, video games, sports, hobbies, etc. If your addiction is another person OR imagining a life with another person (a REAL person, a fantasy person), then THAT is an EA because you are taking your time, energy, emotions, etc. AWAY from your current relationship and investing them elsewhere (even if it's just in your own head.)